Re: APPC refraction correction question

Konstantin von Poschinger


as I have tested a single line DEC arc is not working! I have done this night a 3 line one and got round stars eaven with 900 sec images!


Konstantin v. Poschinger

Hammerichstr. 5
22605 Hamburg

Am 31.07.2020 um 21:43 schrieb Craig Young <craig.young.m8@...>:

I will give that a try on my next clear night.  First, I will create a new model with two DEC arcs, with the target DEC arc sitting between the two sample arcs.  That way the model straddles equally either side of the target arc.  Next, I will compare the tracking results: a) a single DEC arc model with refraction off, b) a single DEC arc model with refraction on and Offset error terms disabled, c) two DEC arc model with refraction enabled.  I'll come back here with the results after the test, hopefully soon.  If others are already doing this it would be good to add in their results to see which of these methods works best.  What we are looking for is the method providing the most accurate unguided imaging run, say a 1 hour run and looking at the quality of the stars (roundness) over that period (or tracking errors if using more analytic software like ATrack).

We can also use these test results as a benchmark for when Ray brings out the DEC arc feature in APPM.  So the more experience we can get from actual user experiences will help to evaluate the new feature and maybe provide some good feedback to Ray as he is designing the new feature.  The AP mounts are more than capable of reaching high performance unguided imaging over long periods of time with small plate scales.  What we need now is to perfect the methodology/software to match the hardware.


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